Almost half of childhood cancer cases worldwide go undiagnosed, says a team of Harvard University researchers who analysed data of the World Health Organisation. The report published in Nature (March) says that in 2015, 397,000 children under-15 globally were afflicted with cancer, and 43 percent of these cases were undiagnosed.

The figures are much higher than of official cancer registries, meaning that tens of thousands of children each year are untreated, and eventually die with the disease undiagnosed. “Because a lot of children don’t have access to primary care, they don’t have access to cancer specialists and their cancers are undiagnosed,” says Zachary Ward, a health-policy researcher at Harvard University, USA. Ward’s research team predicts that, between 2015 and 2030, 6.7 million children worldwide will be afflicted by cancer. According to Ward, if health-care systems don’t improve, 2.9 million of these won’t be detected.